Ouch, forgot that. Well, I guess the database could use Null values internally, but they should be translated into exceptions as soon as possible - as in, throw

Ouch, forgot that. Well, I guess the database could use Null values internally, but they should be translated into exceptions as soon as possible - as in, throw a NullFieldException if the field is accessed. However, checking for these all the time would be just as wasteful as checking for null values. I now see the advantages of the monad way.